In a conventional absorption-type air conditioner, an absorption chamber is formed from a pipe which is installed vertically, and an absorption liquid is provided to flow downwardly from the top of the pipe along an inner surface of the pipe. The absorption liquid absorbs water vapor or coolant vapor contained within the pipe. This arrangement allows the absorption chamber to have a large area for interface between the water vapor or coolant vapor and the absorption liquid, relative to the size of the absorption chamber. Consequently, a relatively compact absorption chamber is possible.
However, in the absorption chamber provided according to conventional practice, the entire inner surface of the pipe is not used effectively because the absorption liquid tends to flow straight down the inner surface of the pipe under the influence of gravity. Further, the absorption liquid flows down the entire length of the pipe in a short period of time and therefore does not effectively absorb the water vapor or coolant vapor. As a result, the conventional absorption chamber structure has a low cooling efficiency. Moreover, the cooling efficiency of the conventional absorption chamber is further reduced by the fact that a large portion of the absorption liquid does not contribute to the absorption of the water vapor or coolant vapor. This is because the rather straight path of flow of the absorption liquid causes little mixing or stirring within the absorption liquid. The water vapor or coolant vapor is absorbed at the surface of the absorption liquid, but the lack of stirring or mixing within the absorption liquid prevents most of the absorption liquid from coming in contact with the water vapor or coolant vapor as the absorption liquid flows downwardly through the pipe. In an attempt to improve the efficiency of this apparatus, it has been proposed to provide a pump to recirculate the absorption liquid back to the top of the pipe. However, this approach tends to make the structure rather complex, and adds requirements for controlling the pump, so that the cost of the apparatus is increased.